Belt-shifting devices.



No. 627,49I. Patented lune 27, |899.. G. F. EVANS.

BELT SHIFTING DEVICE.

(Application led Feb. 20, 1899.) (No Model.) 2 Sheets-Sheet l.

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no. 627,49l. Patented :une 27, |899. a. F. EVANS.

BELT SHIFTING DEVICE. (Application med Fab. 2o, 1699.)

lfri-iras BELT-SHIFTING DEVICE.

SPECIFICATION forming part of Letters Patent No. 627,491, dated June 27,1899.

serai 110.706,14?. (No man.)

To @ZZ whom it may concern: f

Be it known that I, GEORGE F. EVANS, a citizen of the United States,residing at Boston, in the county of Suffolk and Commonwealth ofMassachusetts, have invented a new and useful ImprovementinBelt-Shifting Devices, of which the followingis a specification.

This invention relates toa manner of transmitting motion from onecone-pulley to another without arresting the motion of either, in whicha pair of reversely-tapering cones are placed in close proximity to butfree from contact with one another, and the employment, in combinationwith such pulleys, of an endless driving-belt loosely encircling onepulley and traveling between the two, the frictional pressure or contactof the said pulleys upon this belt serving to transmit motion from oneto the other of the former, mechanical means being combined With thebelt and pulleys, where the distance between the latter may be varied,to compensate for the diminishing thickness of the belt during use, aswell as means by which the belt may be shifted in position along thepulleys to vary the speed' transmitted from the driver to the drivenone.

A notable instance of the class of cone-pulley propulsion to which mypresent invention relates may be seen in Letters Patent cf the UnitedStates numbered 299,231, issued on the 27th day of May, 1884, to lVesleyE. Laird, and also in Letters Patent of the United States numbered374,296 and 390,216, respec-` tively, and issued to myself on the 6thday of December, 1887, and the 2d day of October, 1888.

My invention has reference to the mechanism for shifting the position ofthe driving-belt along the pulleys, its purpose being mainly to enablethe operator to eect considerable changes in the position of the beltrapidly and easily and to provide means f for locking the belt-shaftwhen at rest immovably to its support. In the Laird patent before quotedthis belt is shifted or adjusted by means of a movable carrier orshifter which,,accordingly as it is moved toward the larger or smallerends of the driving-pulley-that is, the one encircled by the belt-Willshiftthe beltand accelerate or diminish the speed of the driven pulley,said shifter being controlled-and actuated by means of a windlass-shaftand cord, said cord being suitably secured at opposite ends tosuch-Windlass and passing about pulleys pivoted to the machine-housings, the remaining ends of the cord being secured toopposite sides of the shifter in such manner that, according to thedirection in which the Windlass is turned, the belt will by means of thecord be shifted toward the larger or smaller ends of the driving-pulley.In this manner of shifting the belt the stretching of the cord preventsto a considerable extent one very 'desirable result-namely, a u niformand constant speed of the counter-shaft. In my two patents above quotedI have endeavored to provide against this objection by the employment ofa screw-threaded shaft which extends through the shifter and lengthwiseof the pulleys and is mounted in bearings in the housings or hangers ofthe machine. In these two latter instances the mechanism employed foractuating the belt-shifter (or shipper, as it is commonly termed) isslowin action, and the purpose of my present invention is to effectthree results: First, to provide suitable mechanism for rapidly shiftingthe position of the belt to any given extent upon the drivingpulley,whereby the operator may by simply pulling a loosely-hanging cord orchain situated closely to his hand be able to effect both the releaseand moving of the belt-shifting device, and consequently of the belt,said shifter while at rest being locked firmly and immovably to itssupport; second, to so construct the belt shifter or carrier that itshall when in its inactive or normal position be locked directly andimmovably to its su pport, and, third, to so construct the belt-shipperthat when released from the pull upon the cord it shall automaticallylock itself rigidly to its support. To effect these objects, I employ inplace of the windlass and cord and the screw-threaded shaft foractuating the shifter a stationary rigid rod or bar, which extendslengthwise of and practically parallel with the adjacent surfaces of thepulleys and is secured at its opposite ends in bearings in the housingsor hangers of the machine. The belt-shifter is a carriage which embracesthe belt and is mounted upon and capable of sliding toyand fro on therod and is controlled and actuated by means of a loosely-hanging cord,vthe ends IOD of which are secured, respectively, to opposite sides ofthe said carriage. The ends of the cord in lieu of being connecteddirectly to the carriage are secured, respectively, to spring-actuatedtwin cam-levers pivoted to opposite sides of said carriage and operating with and gripping the rod in such manner that a pull upon the cordresults in releasing the hold of the carriage upon the red and permitssuch carriage to be pulled upon the rod in either direction, while uponreleasing the cord the levers by the action of their springs are causedto firmly grip the rod and hold the carriage firmly in place thereupon.

The drawings accompanying this specification represent in Figure 1 aperspective view of a pair of cone-pulleys and their supports providedwith my improvements. Fig. 2 is a sectional plan, on an enlarged scale,of the belt-shifter. Fig. 3 is a section, also on an enlarged scale, ofthe belt-shifter, while Fig. 4 is a cross-section, enlarged, of the twocones, the endless belt, and the belt-shifter. Figs. 5 and G in thedrawings represent modifications (to be hereinafter described) of thedevice for releasing the belt-shifter.

In the drawings, l 2 represent a pair of reversely-tapering cone-pulleysarranged in close proximity to but free from contact with one another,the space between them being such as to receive with a tight grip theend` less belt which travels between them, the journals of thesecone-pulleys being mounted in bearings in the housings of themachineframe, these housings (or hangers, as the case may be) beingshown, respectively, at 4 4.

The endless driving-belt is shown at 5 as loosely encircling thedriving-pulley 1 and traveling between and tightly gripped by the twopulleys, the fricticual pressure upon the belt serving to transmitmotion from the driving-cone 1 to the receiving-cone 2.

G in the drawings denotes a rigid rod or bar which is secured at itsopposite ends to the housings 4 4', such rod extending lengthwise of andpractically parallel with the adjacent surfaces of the pulleys.

The belt-shifter is shown in the drawings at 7 as a U -shaped carriagecomposed of a base or body 8 and right-angular arms 9 9. Theright-angular ends or heads 92 92 of the arms 9 9 are pierced to receivethe rod 6, thereby enabling the carriage to slide freely upon such rod.Each arm 9 9' is recessed, as shown at 10, to receive a camlever 11,each lever being pivoted within its recess by a pivot 12. The inner endof each cam-lever 11 is preferably grooved, as shown at 13, to partiallyembrace the rod 6 and provide considerable bearingsurface, while betweenthe inner and shorter arm of each lever and the bottom of its recess isplaced a spring 14, which exerts its stress to crowd the tail orgripping end of each lever tightly against or upon the rod and therebylock the shifter-carriage immovably upon or to the latter.

The belt 5 is embraced by the arms 9 9 of the carriage 7 and is therebycaused to change its position or be shifted upon the pulleys in responseto any change in position of the carriage upon its supporting-rod.

15 in the drawings denotes a cord or its equivalent secured at oppositeends to the tails of the lever 1l, respectively, and preferably passingabout pulleys 16 1G, pivoted to the machine-housings at opposite ends ofthe rod G, the body of this cord hanging loosely from the pulleys into aposition where an operator at work at a lathe or other machine mayreadily grasp it without changing his position. As herein shown, thiscord is in one piece for the reason, as before stated, that the operatormay grasp it without changing his position; but it may be in two pieces,one hanging from each lever.

By means of the above-described arrangement of the pulleys, belt, andshipper it will be vseen that when it is desired to shift the belt toincrease or diminish the speed of the driven pulley or a counter-shaftthe operator will seize the cord in both hands and by pulling upon thesame will release both cam-levers and by so doing free the carriage fromits hold upon its supporting-rod and permit it to be drawn in one or theother direction, as circumstances require. Vhen the proper speed hasbeen imparted to the driven pulley, the operator releases his hold uponthe cord and the cam -levers by the stress of their springsautomatically return to their normal positions and grip the rod 6,thereby locking the carriage 7 to such rod.

The purpose of the cord is simply to release the cam-levers and adjustthe position of the shifter upon the rod 6. At all other times it isidle.

In lieu of the automatically-closing calnlevers before described forlocking the beltshifter to its supporting-rod a sliding wedge or othermechanical equivalent may be employed. I consider my invention in thisrcspect to consist in the combination, with the pulleys, endless belt,and supporting-rod, of a belt shifting carriage adapted to freelytraverse such rod and provided with means for enabling such carriage toautomatically lock itself to the rod. For instance, Fig. 5 of thedrawings represents a modification in which twin wedges 1S 18 areemployed. In this instance each wedge is received within a cell orrecess 19, formed in each arm 9 of the carriage, and' is crowded inwardand upon the rod 6 by means of a spring 20, which ex- IOO IIO

erts its 'stress between a lateral lip 21 formed upon the inner end ofsaid wedge and an abutment 22 within the recess 19. Each wedge isnecessarily parallel with the rod 6, and its outer end or tail ispierced to receive the hand pull-cord.

In Figs. 5 and 6 the part corresponding to that marked 8 in Figs. 1 to4, inclusive, is marked Sl 8, respectively.

Fig. 6 of the drawings represent a modification which is constructed asfollows: The

carriage in this instance is composed simply of a block 23, which slidesat its base loosely upon the rod 6. 2424 represent twin levers disposedupon opposite sides of the carriage and which toward their outer endsare pivoted to the carriage by a common pivot 25. Between the outerextremities of the said levers 24 is placed a coiled spring 26, whichtends to crowd said extremities apart. The inner end of each lever 24terminates in a tubular head 27, the bore 28 of which is tapering andincreasing in diameter toward its outer end, as shown at 29. The innerend of the bore is but slightly larger than the diameter ot' the rod 6.The head of each lever is' pierced, as shown at 30, to receive thehand-cord. In their normal position the levers 24 are crowded upon therod 6 by the action of their springs. When the cord is pulled, the head27 of each lever is released from its grip upon the rod, and when thecord is idle such head automatically grips the rod through theinstrumentality of the spring 2G.

I claim-- l. The combination, with the pulleys and their supports, andthe endless driving-belt gripped and travelingbetween such pulleys, andserving, by frictional contact, to impart motion from one to the other;of a slidingl belt-shifting device, provided with gripping parts and asupport on which it slides,where by, by a pull upon a cord connectedwith such shifting device, the latter may be iirst freed from its holdvupon its support, and then moved upon `the latter, as circumstancesrequire, essentially in manner as hereinbefore set forth.

2. The combination, with the pulleys and their supports, and the endlessbelt gripped and traveling between such pulleys, and serving byfrictional contact to transmit power from one to the other; of a slidingbelt-shifting device, provided with gripping parts and a support onwhich it slides, whereby, by a pull upon a cord connected with suchshifting device, the latter may be first treed from its hold upon itssupport, and then moved upon t-he latter, as circumstances require; andthe cam-levers, for automatically closing said levers upon the supportof` the shifting device, when thepull upon the cord is released,essentially in manner and for the purposes explained.

3. The combination with the pulleys and their supports, the endless beltgripped by and traveling between such pulleys, and a beltshifting deviceoperating to automatically grip its support, of a cord connected withsuch shifting device, and adapted,vby a pull upon it, to release thehold of the shifting device upon its support, substantially asexplained.

4. The combination with the pulleys and their supports, the endless beltgripped by and traveling between such pulleys, and a beltshifting deviceoperating to automatically grip its support, of a cord connected withsuch shifting device and adapted by a pull upon it to first release thehold of said shifting device upon its support, and then to change theposition of such shifter upon said support, substantially as described.

The combination with the pulleys and the endless belttraveling betweenand gripped by them, of a belt-shifting device and a suitable supportfor the same, on which it slides, means for pulling on said device tofree and move the same, and mea-ns whereby it is automatically lockedtoits support when free from the control of the operative, substantiallyas explained.

6. The combination with the pulleys and the endless drivin g-beltgripped by and traveling between such pulleys, of a belt-shifting deviceand a suitable support for the same, said shiftin g device beingconstructed and operating substantially as hereinbefore described,

to automatically lock itselt` toits support, substantially as explained.

7. The combination with the pulleys and the endless belt gripped by andtraveling between such pulleys, of a belt-shifting device and a suitablesupport for the same, said shifting device beingconstructed andoperating substantially as herein described to automatically lock itselfto its support; and a suitable mechanism for effecting such locking, anda handcord connected therewith, essentially as here- 4 in set forth.

S. The combination with the pulleys and the endless belt gripped by andtraveling between them, of the carriage straddling such belt a suitablesupport upon which said carriage slides, and a device for automaticallylocking the two together, essentially as explained.

9. The combination with the pulleys and the endless belt gripped by andtraveling between them, of the carriage straddling such belt a suitablesupport, a device for automatically locking the two together, and ahand-cord connected with and operating said locking device,substantially as explained.

l0. The combination with the pulleys, and the endless belt travelingbetween and gripped by them, and the rod for supporting thebelt-shifter, of the belt-shifting device consisting of the carriage,with its body inclosing and adapted to slide upon its supporting-rod,its arms or wings to embrace the belt and the spring-impelled cam-leversoperating to grip the supporting-rod, andthe hand-cord for operatingsaid .levers and carriage, substantially as described.

GEORGE F. EVANS.

Witnesses:

' FRANCIS L. BULLARD,

FRED G WEBBER.

IOO.

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